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Generic (top level) Metadata constructor and methods

Source: R/class_Metadata.R
Metadata.Rd

The Metadata S3 class holds information, such as name, date, author and file, as a named list with elements of length one. The Metadata is essentially a list therefore list methods are also applicable.

Usage

Metadata(entries = list())

# S3 method for class 'Metadata'
validate_object(x)

# S3 method for class 'Metadata'
length(x)

# S3 method for class 'Metadata'
names(x)

# S3 method for class 'Metadata'
x[i]

# S3 method for class 'Metadata'
x[i] <- value

# S3 method for class 'Metadata'
x[[i]]

# S3 method for class 'Metadata'
x[[i]] <- value

# S3 method for class 'Metadata'
save(x, file = "metadata.json")

# S3 method for class 'Metadata'
read(x, file)

# S3 method for class 'Metadata'
show(x)

Arguments

entries

A named list of metadata entries as elements. Default is an empty list. Elements must be of type character, numeric or POSIXt and must have length 1.

x

A Metadata object.

i

A numeric or character vector with the index or name of the entry to replace.

value

The new value to replace the entry.

file

A character string with the file name to read the metadata from. The file format should be either "json" or "rds".

Value

A Metadata S3 class object which is fundamentally a named list with metadata entries.

Details

If not given, elements name, author, date and file are set to NA_character_, NA_character_, current system time and NA_character_, respectively.

Methods (by generic)

  • validate_object(Metadata): Validates the Metadata object, returning NULL if valid.

  • length(Metadata): Returns the length of the metadata entries.

  • names(Metadata): Returns the names of the metadata entries.

  • [: Subsets the metadata entries.

  • `[`(Metadata) <- value: Replaces metadata entries.

  • [[: Extracts a single metadata entry.

  • `[[`(Metadata) <- value: Replaces a single metadata entry.

  • save(Metadata): Saves the metadata to a file.

  • read(Metadata): Reads metadata from a file, returning a Metadata object.

  • show(Metadata): Prints the metadata entries.